From: Kbwms AT aol DOT com
Message-ID: <10fee054.36890e34@aol.com>
Date: Tue, 29 Dec 1998 12:15:32 EST
To: eliz AT is DOT elta DOT co DOT il
Cc: djgpp-workers AT delorie DOT com
Mime-Version: 1.0
Subject: Re: info fails to clear the screen
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Reply-To: djgpp-workers AT delorie DOT com

Dear Eli Zaretskii,

On 12-29-98 at 03:25:20 EST you wrote:
>
>
> On Mon, 28 Dec 1998 Kbwms AT aol DOT com wrote:
>
> > I notice that info (from txi312b of 16 Sep 98) fails to clear the screen
> > upon exit.
>
> Info doesn't clear the screen on purpose.  The screen is cleared as a
> side effect of changing the screen dimensions (i.e., the number of
> rows or columns displayed on the screen).  That's how the BIOS
> functions used by Info work.  Info actually tries to avoid clearing
> the screen, by not switching the video mode unless it has to.  (I find
> this behavior justified because sometimes you would like the
> information be still on screen for you to be able to read it when you
> do whatever you needed to invoke Info for.)
>

The previous version cleared the screen at exit.  Nothing has changed on
my end, so I assume Info has changed.

> The above means that if Info uses the same screen dimensions as those
> you usually run your system, the screen will not be cleared.  For
> example, if your monitor is in the default 80x25 mode, and Info is not
> instructed to switch to other dimensions once it starts, the screen
> will not be cleared upon exit.
>
> The default setup of Info is to switch to 80x40 display, because
> DJGPP.ENV has this snippet in the [info] section:
>
>   +INFO_LINES=40
>

I see no such entry in my DJGPP.ENV file, which is about seven months
old.  I have yet to update to V2.02 because I'm chicken.  I'll add an
entry like that one and see how things go.

> However, if you have edited this line, or renamed info.exe into
> something else, or set INFO_LINES in the environment to a different
> value, you might have a situation where the screen dimensions inside
> and outside of Info are identical, and then the screen is not cleared
> on exit.
>

My monitor runs in 80x25 mode.  The version of Info that I'm using came
from txi312b.zip, not source files.  Evidently, something has changed in
the two years (more or less) between versions.  I'll let you know how the
+INFO_LINES=40 entry treats me.

> Is this behavior a problem?

For my part, the preferred behavior is to have the screen returned to
its former status.  Many of the text editors work that way and I have
written programs that do likewise.


K.B. Williams